DEP to Conduct Timed Reservoir Releases To Prepare for Work on Delaware Aqueduct

New Technology Will Allow Releases to Support Downstream Recreation

Environmental Protection Commissioner Cas Holloway today announced a planned shutdown of the Rondout-West Branch Tunnel portion of the Delaware Aqueduct this fall to perform the next phase of work related to the long-term repair of the tunnel. In October, DEP will install a backup support — a giant plug — behind an existing hatch that ensures that water in the tunnel does not go into the shaft, which workers need to access to install pumping equipment that will be used during the long-term repair. Ahead of the three-week shutdown, DEP has agreed with the states of Delaware, New York, New Jersey and Pennsylvania on a program, starting today, to manage the incremental release of water from reservoirs during the summer months that otherwise would be diverted during the planned shutdown. The new program is possible in part because of DEP's new computer modeling system that enables water supply operators to better predict water storage levels in the City's reservoirs.

"It's vital that we continue to take the steps necessary to improving our water infrastructure," said Commissioner Holloway. "Under Mayor Bloomberg's leadership, we have made it a priority to prepare for the eventual repair of the Delaware Aqueduct, which provides half of the City's drinking water supply and has been in service since 1944. In advance of the latest round of work, DEP will make incremental water releases to support recreational activities downstream, such as trout fishing. These timed releases are now possible in part due to new technologies we are pioneering to help us better predict and manage our reservoir levels to meet the daily water needs of 9 million New Yorkers."

Because of tools being developed to help better manage the water supply, DEP will be able to divert or release water from its reservoirs at the best times this summer to guarantee the highest quality water is delivered to New Yorkers and to benefit downstream habitat and recreation activities. In February, DEP announced that work had begun on the Operations Support Tool, a cutting-edge, $5.2 million computer system that will enable DEP's water supply operators to more accurately predict water storage levels in the City's reservoirs so that DEP can better manage the movement of water throughout the reservoir system, and ultimately, to the 9 million New Yorkers who rely on the City's drinking water every day. The initiative, the first of its kind in the world, will improve the City's water management systems by predicting events that could affect water quality much earlier than is now possible, and incorporating more data in the computer models used to determine water flows. It is being implemented on a rolling basis and is expected to be complete by 2013.

The 85-mile Delaware Aqueduct is the world's longest continuous tunnel and conveys drinking water from the Cannonsville, Neversink, Pepacton, and Rondout reservoirs to the City's distribution system, and provides approximately 50 percent of the City's daily water needs.

Since 2002, Mayor Bloomberg has invested approximately $493 million in preparation work for the eventual repair of the Delaware Aqueduct. The City has committed another $100 million for additional work over the next four years.

The shutdown will allow workers to perform work on a shaft necessary to ultimately repair the Aqueduct. Earlier this year, divers investigated the area around an existing hatch in the shaft that leads to the Aqueduct. In the fall, this area will be reinforced, which will lay the groundwork for the next phase of work, the installation of a pumping station in the shaft.

Over the next 12 months, DEP will temporarily increase the amount of water available for release from its Delaware Basin Reservoirs as part of the Flexible Flow Management Plan, an agreement between the four basin states of Delaware, New Jersey, New York, Pennsylvania, and the City of New York to manage the water storage levels and releases of the Cannonsville, Pepacton, and Neversink reservoirs.

DEP manages the City's water supply, providing more than 1 billion gallons of water each day to more than 9 million residents, including 8 million in New York City, and residents of Ulster, Orange, Putnam and Westchester counties. DEP has invested over $1.5 billion in watershed protection programs — including partnership organizations such as the Catskill Watershed Corporation and the Watershed Agricultural Council — that support sustainable farming practices, environmentally sensitive economic development, and local economic opportunity. New York City's water is delivered from the Catskill, Delaware, and Croton watersheds that extend more than 125 miles from the City, and are comprised of 19 reservoirs, and three controlled lakes.